1. Field of the Invention
The present invention relates to a valve including a valve plug, which is displaced under the supply of a pressure fluid or an electric current, for switching a communication state of a fluid passage by opening and closing operations of the valve plug.
2. Description of the Related Art
Heretofore, a valve has been used for controlling a flow through state of a pressure fluid by supplying a pressure fluid to an actuator, or alternatively, by discharging compressed air to the atmosphere.
Such a valve, for example, as disclosed in Japanese Laid-Open Patent Publication No. 2006-083879, is equipped with a body having a fluid passage therein through which a fluid flows, a valve plug, which is disposed for displacement in the interior of the body, and a solenoid unit connected to the body and having a coil that is excited upon supply of an electric current thereto. A magnetic force is generated by energizing the solenoid unit, whereby the valve plug is opened by displacement of a movable iron core. Additionally, a diaphragm is disposed between the solenoid unit and the body. An inner circumferential side of the diaphragm is inserted into an annular groove of a shaft connected to the valve plug, whereas the outer circumferential side of the diaphragm is sandwiched between the body and the solenoid unit, so that leakage of pressure fluid between the solenoid unit and the interior of the body through which the fluid flows is prevented.